High severity · published Dec 8, 2021
CVE-2021-43534
Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2
8.8
CVSS
1.2%
EPSS
No
On KEV
Description
Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.2% · higher than 69% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 94.0 · source: NVD
DL
Debian Linux · Debian
9.0; 10.0; 11.0 · source: NVD
FE
Firefox Esr · Mozilla
before 91.3.0 · source: NVD
TH
Thunderbird · Mozilla
before 91.3.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-43534
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-43534
Broken Link
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1606864%2C1712671%2C1730048%2C1735152
Mailing List
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
Mailing List
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
Third Party Advisory
https://www.debian.org/security/2021/dsa-5026
Issue Tracking
https://www.debian.org/security/2022/dsa-5034
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-48/
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